1. Field of the Invention
The invention relates to an improved aquarium heater and particularly an aquarium heater that is capable of cutting off the electric circuit of the heater when overloaded to protect the safety of the heater and usage.
2. Description of the Prior Art
These days aquariums are not only for growing aquarium fish, they also may be used as ornamental articles to match interior design and landscape decoration to foster pleasant atmosphere of households or working environments. Maintaining water stability is a very important issue for aquariums. Water temperature and impurity in the aquarium have to be controlled properly to enable fish and plants to live and flourish. Conventional heaters for controlling water temperature heat the water when electricity is supplied. While it is possible to set the temperature of heating, they generally do not have safety designs. If overload occurs during heating process, the heater is burnt out if users do not take remedy action properly and timely. It causes a lot of safety concerns. Although some heaters have included a fuse for protection purpose, the fuse is located inside the heater. Once the fuse is burnt out, the hater has to be discarded and cannot be repaired. It is a waste and an unnecessary burden to users.
In view of the aforesaid disadvantages, the primary object of the invention is to provide an improved aquarium heater that can prevent the risk when the heater is overloaded during heating.
The aquarium heater according to the invention includes a protective device equipped with an elastic strip switch bridging between a heating coil and a circuit board. When the total circuit is overloaded, circuit operation may be shut down to protect the safety of the heater.